For each of the festivals below, we have selected a number of acts that we categorize as either Likely (no guarantees, but we have good reason to believe that they will headline next year) or Possible (far more speculative, but not simply picked out of a hat) to Probable (still speculative, but we have particular reason to think their stars will align). Additionally, under the Don't count them out heading, we name two or three acts that we think just might join LCD's reunion/revivification party in 2016.
Likely: LCD Soundsystem, Lana del Rey
Probable: Dan Auerbach's The Arcs, The Libertines
Possible to Probable: Radiohead, perhaps The National
Possible in addition or instead: any one and perhaps two of Coldplay, Gorillaz, Iron Maiden, Kanye West, Metallica, and maybe Mumford and Sons, Beyonce, Paul McCartney, or the Rolling Stones.
Don't count them out: N.W.A., or maybe Guns 'n Roses
Possible: The Dixie Chicks
Likely: Radiohead and/or Phish
Probable: Lana del Rey
Possible: The National, The xx
Possible to Probable: The Arcs, Drake, Lana del Rey, and perhaps AC/DC or Black Sabbath
Don't count them out: Fleet Foxes
Keep in mind that it is difficult to make predictions at this early date and that circumstances may change.
It is even less advisable to forecast festivals later in 2016, but we will nevertheless note a few interesting Lollapalooza possibilities, including a headlining appearance by hometown favorite Kanye West (and/or a reunited N.W.A.), a performance arising out of the new electronic dance music project from another native Chicagoan, Rage Against the Machine's Tom Morello, and what might be a rare 2016 show by Jack White and Alison Mosshart's The Dead Weather.
As for Outside Lands, we think that there is a decent possibility that it will feature local heroes Green Day and/or one of the new groups from local legend Carlos Santana. And we take interest in the prospect of a new "America Rocks" festival in late June in Rhode Island, with organizers bandying about names like Metallica, The Black Keys, and Arctic Monkeys. The last, if they return in 2016, will also be top prospects for one or two of the later festivals above.
We will be back later in the year and early the next with more as information develops...